Electrochromic device with separately controllable zones

Abstract

An electrochromic device includes a first substrate having a first conductive surface, a second substrate having a second conductive surface, and a sealing member joining the first conductive surface of the first substrate to the second conductive surface of the second substrate. The electrochromic device also includes a first busbar spaced apart from a second busbar and both in electrical communication with the first conductive surface of the first substrate, and a third busbar spaced apart from a fourth busbar and both in electrical communication with the second conductive surface of the second substrate. The first substrate, the second substrate, and the sealing member define a chamber. The first busbar is electrically connected with the third busbar to define a first zone. The second busbar is electrically connected with the fourth busbar to define a second zone.

What is claimed is: 
     
         1 . An electrochromic device comprising:
 a first substrate having a first conductive surface;   a second substrate spaced apart from the first substrate and defining a chamber therebetween, the second substrate having a second conductive surface;   an electrochromic medium disposed in the chamber;   a first busbar and a second busbar on the first substrate; and   a third busbar and a fourth busbar on the second substrate,   wherein:
 the first and third busbars define a first zone; 
 the second and fourth busbars define a second zone; 
 a transition zone is defined by a gap between the first and second zones; and 
 the transition zone is operable to gradually transition a color of the electrochromic medium between the first zone to the second zone. 
   
     
     
         2 . The electrochromic device of  claim 1 , wherein:
 the first zone is operable to a first state of transmissivity by applying a first voltage across the first and third busbars;   the second zone is simultaneously operable to a second state of transmissivity by applying a second voltage across the second and fourth busbars;   the first and second voltages are different; and   the first and second states of transmissivity are different.   
     
     
         3 . The electrochromic device of  claim 1 , wherein:
 the first zone is operable to a colored state by applying a first voltage across the first and third busbars; and   the second zone is simultaneously operable to a colorless state by applying no voltage across the second and fourth busbars.   
     
     
         4 . The electrochromic device of  claim 3 , wherein:
 the first and third busbars form a first electrical circuit; and   the second and fourth busbars form a second electrical circuit.   
     
     
         5 . The electrochromic device of  claim 1 , wherein the color of the electrochromic medium gradually varies from the first zone to the second zone. 
     
     
         6 . The electrochromic device of  claim 1 , wherein the first zone and the second zone are each separately addressable. 
     
     
         7 . The electrochromic device of  claim 1 , wherein a partially colored state is operably obtained by applying a voltage across the first and the third busbars. 
     
     
         8 . The electrochromic device of  claim 1 , wherein:
 the first busbar and the second busbar are spaced apart from one another by a first gap; and   the third busbar and the fourth busbar are spaced part from one another by a second gap.   
     
     
         9 . An electrochromic device comprising:
 a first substrate having a first conductive surface;   a second substrate having a second conductive surface;   an electrochromic medium disposed between the first substrate and the second substrate;   a first busbar spaced apart from a second busbar and both in electrical communication with the first conductive surface of the first substrate; and   a third busbar spaced apart from a fourth busbar and both in electrical communication with the second conductive surface of the second substrate,   wherein:
 at least one of the first conductive surface and the second conductive surface is substantially transparent; 
 the first busbar is externally electrically connected with the third busbar to define a first zone; and 
 the second busbar is externally electrically connected with the fourth busbar to define a second zone. 
   
     
     
         10 . The electrochromic device of  claim 9 , wherein:
 each of the first substrate and the second substrate have a first edge and a second edge opposite the first edge;   the first conductive surface of the first substrate is disposed between the first edge and the second edge of the first substrate;   the second conductive surface of the second substrate is disposed between the first edge and the second edge of the second substrate;   the first busbar and the second busbar are proximate to the first edge of the first substrate; and   the third busbar and the fourth busbar are proximate to the second edge of the second substrate.   
     
     
         11 . The electrochromic device of  claim 9 , further comprising:
 a transition zone between the first zone and the second zone;   wherein the transition zone gradually transitions a color from the first zone to the second zone.   
     
     
         12 . The electrochromic device of  claim 11 , wherein: when the first zone is in a colored state, the second zone is in a colorless state, and the transition zone is in a partially colored state, the color varies gradually from the colored state in the first zone to the partially colored state in the transition zone to the colorless state in the second zone without a distinct boundary:
 between the first zone and the transition zone, and   between the transition zone and the second zone.   
     
     
         13 . The electrochromic device of  claim 9 , wherein the first zone and the second zone are each separately addressable. 
     
     
         14 . The electrochromic device of  claim 9 , wherein:
 the first busbar and the second busbar are spaced apart from one another by a first gap; and   the third busbar and the fourth busbar are spaced part from one another by a second gap.   
     
     
         15 . A method comprising:
 connecting a first busbar of a first substrate of an electrochromic device to a third busbar of a second substrate of the electrochromic device to form a first electrical circuit and define a first zone;   connecting a second busbar of the first substrate of the electrochromic device to a fourth busbar of the second substrate of the electrochromic device to form a second electrical circuit and define a second zone; and   applying a voltage across the first electrical circuit in a closed circuit to obtain a first transmissive state in the first zone.   
     
     
         16 . The method of  claim 15 , wherein a transition zone between the first zone and the second zone gradually transitions between the first transmissive state and a second transmissive state of the second zone, the first and second transmissive states being different. 
     
     
         17 . The method of  claim 15 , wherein the external voltage is applied across the first electrical circuit for a first period of time. 
     
     
         18 . The method of  claim 17 , further comprising:
 removing the external voltage across the first electrical circuit after expiration of the first period of time;   configuring the first electrical circuit in an open circuit for a second period of time; and   applying no external voltage across the second electrical circuit in the closed circuit,   wherein:
 the first zone remains in the first transmissive state; and 
 the second zone remains in the second state. 
   
     
     
         19 . The method of  claim 18 , further comprising:
 maintaining the first electrical circuit in the open circuit; and   applying a external voltage across the second electrical circuit,   wherein:
 the first zone transitions to the second transmissive state after the expiration of the second period of time; and 
 the second zone remains in the second transmissive state. 
   
     
     
         20 . The method of  claim 18 , wherein the second period of time is greater than the first period of time.